[The] DRD2 gene variant . . . has previously been tied to a propensity for violence, alcoholism, attention-deficit/hyperactivity disorder and several other psychiatric conditions. . . other research questions whether any link exists between DRD2 and mental ailments.
The latest study (D. Lee et al. The effect of the Great Recession and dopamine receptor gene DRD2 on maternal harsh parenting. American Sociological Association meeting, Las Vegas, August 22, 2011) suggests it it also influences how mom's parenting styles change as a result of the stress of a recession.
Mothers who inherited either one or two copies of a particular form of the dopamine D2 receptor gene, dubbed DRD2, cited sharp rises in spanking, yelling and other aggressive parenting methods for six to seven months after the onset of the economic recession in December 2007. . . . Hard-line child-rearing approaches then declined for a few months and remained stable until a second drop to pre-recession levels started around June 2009. . . . Mothers who didn’t inherit the gene variant displayed no upsurge in aggressive parenting styles after the recession started[.]
DRD2 (citing 50 scholarly studies) is one of a dozen or so relatively common genes linked to mental health conditions (links e.g. here) that verge on extreme personality types that are associated with a range of antisocial or sometimes dysfunctional behavior (for example earning low GPAs in college relative to one's test scores) in modern society. DRD2 is independent of IQ.
Some of the other genes that attract attention are AVPR1a (the "bad husband gene"), DAT1 (a less powerful dopamine regulator), DRD4 (a dopamine regulator), DRD3 (a dopamine regulator), FOX2 (language), MCPH1 (brain development), HTR2B (impulsivity), LPHN3 (ADHD), 5-HTT (vulnerability to psychological trauma).